This is a a three-arm, open-label, randomized, multi-center, Phase III study to compare the virologic efficacy and safety of the three drug combinations of 3TC, ZDV, and IDV (ARM 1) to the four drug combinations of 3TC,ZDV,IDV, and EFZ (ARM II) and 3TC,ZDV,IDV, and NFV (ARM III). Primary treatment comparisons will be between the three drug combination arm and each of the two four drug combination arms. A total of 444 subjects will be randomized with stratification by CD4 cell count (< or = 50 cells/mm# versus > 50 cells/mm3, HIV RNA ( < or = 40,000 copies/ml versus > 40,000 copies/ml) and prior use of nucleoside analogue therapy (excluding 3TC) (no prior therapy versus any prior therapy). Subjects with prior use of 3TC, any non-nucleoside analogue or protease inhibitor will be excluded at entry. Accrual is anticipated to take 24 weeks and follow-up is planned to continue for 72 weeks after the last subject is randomized.